Sailsjs: How to populate association after *update* to model? - node.js

Question

I have the following controller code that works for index, show, create methods but the update fails when I include populate - what am I doing wrong?
// User List
index: function(req, res) {
User.find()
.populate('profile')
.exec(function(err, users) {
if (err) return res.json(err, 400);
if (!users) return res.json(users, 404);
res.json(users, 200);
});
},
// Single User
show: function(req, res) {
User.findOne({ username: req.param('username') })
.populate('profile')
.exec(function(err, user) {
if (err) return res.json(err, 400);
if (!user) return res.json(user, 404);
res.json(user, 200);
});
},
// Create User
create: function(req, res) {
User.create(req.body, function(err, user) {
if (err) return res.json(err, 400);
Person.create({user: user.id, slug: user.username}, function(err, profile) {
if (err) return res.json(err, 400);
User.update(user.id, {profile: profile.id})
.populate('profile')
.exec(function(err, user) {
if (err) return res.json(err, 400);
});
user.profile = profile;
res.json(user, 200);
});
});
},
// Update User
update: function(req, res) {
var username = req.param('username');
User.update({ username: username }, req.body)
.populate('profile')
.exec(function(err, user) {
if (err) return res.json(err, 400);
res.json(user, 201);
});
},

Answer 1

As per the documentation the update function takes a callback to which it passes the updated records.
Example from the doc :
// For example, to update a user's name,
// .update(query, params to change, callback)
User.update({
name: 'sally'
},{
phone: '555-555-5555'
}, function(err, users) {
// Error handling
if (err) {
return console.log(err);
// Updated users successfully!
} else {
console.log("Users updated:", users);
}
});
Applied to your code, it would look like this :
// Update User
update: function(req, res) {
var username = req.param('username');
User.update({ username: username }, req.body)
.exec(function(err, users) {
if (err) {
return res.json(err, 400);
}
var user = users.slice(0,1); // Take the first user in the array
User.findOne(user.id) // You may try something like User._model(user) instead to avoid another roundtrip to the DB.
.populate('profile')
.exec(function(err, user) {
if (err) {
return res.json(err, 400);
}
res.json(user, 201);
});
});
}

Answer 2

Jeremie your answer is correct in essence but has a few issues:
the user object returned by the update call and then sliced does not
have a populate function
slice the users list returns a list instead of the object desired
Personal preference but I also prefer the following which uses the exec call instead of the callback.
update: function(req, res) {
var id = req.param('id');
User
.update(id, req.params.all())
.exec(function(err, users) {
if(err) return res.json(err, 400);
var user = users[0];
console.log('ID', user.id);
User
.findOne(user.id)
.populate('profile')
.exec(function (err, user){
if (err) return res.json(err, 400);
res.json(user, 201);
});
});
},